TECHNICAL BULLETIN TB-3069
Combo Tester
Installation, Operation and Maintenance
Made in the
United States of America
Per ANSI/ESD S20.20 section 7.4 “A Compliance
Verification Plan shall be established to ensure the
Organization’s fulfillment of the technical requirements
of the ESD Control Program Plan. Process monitoring
(measurements) shall be conducted in accordance
with a Compliance Verification Plan that identifies the
technical requirements to be verified, the measurement
limits and the frequency at which those verifications shall
occur. The Compliance Verification Plan shall document
the test methods and equipment used for process
monitoring and measurements. … The test equipment
selected shall be capable of making the measurements
defined in the Compliance Verification Plan.”
Per ANSI/ESD S1.1 Annex A.3 Frequency of System
Testing “The wrist strap system should be tested daily to
ensure proper electrical resistance.”
Figure 1. Desco 19280 Combo Tester
Description
The Desco Combo Tester verifies the functionality of
an operator’s wrist strap and footwear (footwear test
requires foot plate). It determines if an operator’s wrist
strap and footwear will function correctly. A rocker
switch allows the operator to select a wrist strap or
footwear test. A green light indicates that the wrist strap
or footwear is passing. Red and yellow lights plus an
audible alarm indicate when the wrist strap or footwear is
failing. If failure occurs, the tester will also display if the
grounding device’s resistance is too low or too high.
The Combo Tester may also be used to test smocks
or garments that feature a grounding mechanism for
operators using a coiled cord connection.
The factory test limits are set to:
Wrist Straps:
Footwear:
750 kilohms and 10 megohms
750 kilohms and 100 megohms
Limits meet the required limits for Compliance
Verification of ANSI/ESD S20.20 (Wrist Strap System
< 3.5 x 107 ohms and Footwear < 1 x 109 ohms tested
per ESD TR53).
Per ESD Handbook ESD TR20.20 section 5.3.2.4.2
Additional User Wrist Strap Testing “Proper testing of
the wrist strap includes the resistance of the groundable
point on the end of the cord, the cord itself, the resistor,
the cord-to-cuff snap connector, the resistance of the
interface of the cuff, the cuff/wrist interface, and the
resistance of the person between the wrist and the hand
that contacts the test electrode.”
Per ESD Handbook ESD TR20.20 section 5.3.2.2.2
Wrist Strap Ground Cord “At first glance, the ground cord
appears to be a relatively simple assembly. However,
the design requirements are considerable, given the
wide range of user applications and the durability
requirements of constant tugging, flexing, and dragging
over the edge of workstation tops and equipment
chassis.”
Item
Description
19280
Combo Tester
19282
Combo Tester with Stand and Foot Plate
19283
Combo Tester with Stainless Steel Foot Plate
19261
Combo Tester Mounting Plate
98254
Stand and Foot Plate
Contact Desco Customer Service if custom test limits
are required.
98273
Stainless Steel Foot Plate
The Combo Tester can be powered by a 9 volt battery or
the Desco 98256 (120VAC) and 98257 (220VAC) power
adapters (sold separately). A warning light on the tester
indicates when the battery power is too low and affecting
the test results.
98257* Power Adapter, 220VAC Input, 9VDC Output
Each Combo Tester is calibrated with accepted
procedures and standards traceable to the National
Institute of Standards and Technology (NIST) and
includes a NIST certificate.
98256* Power Adapter, 120VAC Input, 6VDC Output
*Use only the Desco 98256 and 98257 power adapters
with the Combo Tester. Using any other power adapter
may damage the unit and void the warranty.
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
TB-3069 Page 1 of 7
September 2016
© 2016 DESCO INDUSTRIES, INC.
Employee Owned
Packaging
19280 COMBO TESTER
1
1
1
1
Combo Tester
Foot Plate Cord, 5 inches
9V Battery
Certificate of Calibration
19282 COMBO TESTER WITH STAND AND FOOT
PLATE
19283 COMBO TESTER WITH STAINLESS STEEL
FOOT PLATE
1
1
1
1
1
1
Combo Tester
Foot Plate Cord, 5 inches
9V Battery
Stainless Steel Foot Plate
Foot Plate Cord, 6 feet
Certificate of Calibration
1 Combo Tester
1 Foot Plate Ground Wire, 5 inches
1 9V Battery
1 Foot Plate
1 Pedestal
3 Button Head Screws, 1/4-20 x 3/4”
1 Allen Wrench, 5/32”
1 Flat Head Screw, 8-32 x 5/8”
1 Knurled Nut, 8-32
1 Black Cap
1 Poster
1 Certificate of Calibration
Figure 3. Desco 19283 Combo Tester with Stainless
Steel Foot Plate
19261 COMBO TESTER MOUNTING PLATE
1
4
4
4
Combo Tester Mounting Plate
Pan Head Screws, 4 x 1-1/2"
Pan Head Screws, 10 x 1-1/2"
Mounting Anchors
Figure 2. Desco 19282 Combo Tester with Stand and
Foot Plate
Figure 4. Desco 19261 Combo Tester Mouting Plate
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
TB-3069 Page 2 of 7
© 2016 DESCO INDUSTRIES, INC.
Employee Owned
98254 STAND AND FOOT PLATE
1 Foot Plate
1 Pedestal
1 Foot Plate Cord, 5 inches
3 Button Head Screws, 1/4-20 x 3/4”
1 Allen Wrench, 5/32”
1 Flat Head Screw, 8-32 x 5/8”
1 Knurled Nut, 8-32
1 Black Cap
1 Poster
Features and Components
A
C
B
D
E
F
G
Figure 7. Combo Tester features and components
A. 6-9VDC Power Jack: Connect the 98256 or 98257
power adapter (sold separately) here to power the
Combo Tester.
B. Test Result LEDs: Displays the test results.
C. Foot Plate Jack: Connect the banana plug terminal
of the foot plate cord here and the other end to the
pedestal (19282) or stainless steel foot plate (19283,
98273).
D. Rocker Switch: Toggle to the left when performing
a footwear test. Toggle to the right when performing a
wrist strap test.
Figure 5. Desco 98254 Stand and Foot Plate
E. Single-Wire Wrist Strap Jack: Insert your
single-wire wrist cord here to test your wrist strap.
98273 STAINLESS STEEL FOOT PLATE
F. Test Switch: Push down and hold your finger here
to perform a test.
1 Stainless Steel Foot Plate
1 Foot Plate Cord, 6 feet
G. Low Battery LED: Illuminates when the battery
power is low and needs to be replaced.
Figure 6. Desco 98273 Stainless Steel Foot Plate
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
TB-3069 Page 3 of 7
© 2016 DESCO INDUSTRIES, INC.
Employee Owned
Installation
The Combo Tester is portable when powered by a 9V
alkaline battery, but it also has the flexibility of being
permanently installed at a location. Use the three
keyhole slots located on the back of the Combo Tester
to mount it to a wall or stand.
INSTALLING THE 19282 COMBO TESTER WITH
STAND AND FOOT PLATE
1. Position the pedestal on top of the foot plate with
the mounting bracket sloping toward the operator.
Secure the pedestal to the foot plate using the 3
included button head screws and allen wrench.
INSTALLING THE 19280 / 19283 COMBO TESTER
1. Install the 9V alkaline battery into the Combo
Tester.
2. Select a location to mount the Combo Tester.
3. Install three #6 or #8 screws into a wall or other
vertical surface as shown in the figure below. Make
sure that the screw heads do not project out more
than 1/4" from mounting surface.
Figure 10. Securing the pedestal to the foot plate
Figure 8. Combo Tester keyhole slots
4. Mount the Combo Tester onto the screws, and pull
it down to secure it into place.
2. Install the 9V alkaline battery into the Combo
Tester.
5. Set the Stainless Steel Foot Plate below the tester
(if applicable).
3. Mount the Combo Tester onto the pedestal’s
mounting bracket and flat head screw, and screw
down to secure it into place.
6. Insert the 6' long foot plate cord’s banana plug into
the Combo Tester’s foot plate jack.
4. Insert the 5" long foot plate cord’s banana plug into
the Combo Tester’s foot plate jack.
5. Attach the foot plate cord’s ring terminal to the flat
head screw located at the back of the pedestal’s
mounting bracket, and tighten the knurled nut to
secure.
Figure 11. Installing the Combo Tester to the pedestal
Figure 9. Inserting the foot plate cord’s banana jack into
the Combo Tester
7. Snap the opposite end of the foot plate cord onto
the Stainless Steel Foot Plate.
6. Cover the knurled nut and flat head screw with
included insulative vinyl cap.
7. Install the included poster at eye level nearby the
test station.
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
TB-3069 Page 4 of 7
© 2016 DESCO INDUSTRIES, INC.
Employee Owned
4. A “PASS” test result is indicated by illumination
of the green LED. A “FAIL LOW” test result is
indicated by illumination of the red LED. A “FAIL
HIGH” test result is indicated by illumination of the
yellow LED.
If your ESD test fails, check your wrist strap and
ensure that it is being worn correctly and/or needs
to be replaced.
NOTE 1: The Combo Tester may briefly display “FAIL
HIGH” once the test button is released at the conclusion
of a test. Residual voltage in the circuit’s capacitors
causes the test to continue for a split second after the
button is released.
NOTE 2: Failures may be caused by dry skin or minimal
sweat layer. For wrist straps, try using an approved
dissipative hand lotion such as Menda Reztore™ ESD
Hand Lotion to your wrist prior to use.
Figure 12. Completed Combo Tester with Stand and
Foot Plate assembly
Operation
WRIST STRAP TEST
1. While wearing a wrist strap, plug the wrist cord
into the wrist strap jack located on the face of the
Combo Tester.
2. Toggle the rocker switch to the right toward WRIST
STRAP.
3. Push down and hold the test switch until the test
results are displayed. Ensure that your finger
also makes contact with the metal ring around the
pushbutton when performing a test.
FOOTWEAR TEST
1. Toggle the rocker switch to the left toward FOOT
PLATE.
2. While wearing ESD footwear, place one foot on
the foot plate, and lift the second foot off the floor.
Make sure there is no wrist cord plugged into the
WRIST STRAP jack.
3. Push down and hold the test switch until the test
results are displayed. Ensure that your finger
also makes contact with the metal ring around the
pushbutton when performing a test.
DO NOT touch any other metal while performing
your test as this will affect your results.
DO NOT touch any other metal while performing
your test as this will affect your results.
Figure 13. Performing a wrist strap test
Figure 14. Performing a footwear test with the 19282
Combo Tester with Stand and Foot Plate
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
TB-3069 Page 5 of 7
© 2016 DESCO INDUSTRIES, INC.
Employee Owned
4. A “PASS” test result is indicated by illumination
of the green LED. A “FAIL LOW” test result is
indicated by illumination of the red LED. A “FAIL
HIGH” test result is indicated by illumination of the
yellow LED.
If your ESD test fails, check your footwear and
ensure that it is being worn correctly and/or needs
to be replaced.
NOTE 1: The Combo Tester may briefly display “FAIL
HIGH” once the test button is released at the conclusion
of a test. Residual voltage in the circuit’s capacitors
causes the test to continue for a split second after the
button is released.
NOTE 2: Failures may be caused by dry skin or minimal
sweat layer. Footwear test results can be improved
by taking a short walk to build a sweat layer for better
conductivity.
Calibration
The Desco Combo Tester is calibrated to NIST
traceable standards. There are no user adjustments
necessary. We recommend that calibration be
performed annually using the Desco 07010 Calibration
Unit. It is a convenient product which allows the
customer to perform NIST traceable calibration on
single-wire personnel testers. The 07010 is designed
to be used on the shop floor at the workstation, virtually
eliminating downtime, verifying that the tester is
operating within tolerances.
View technical bulletin TB-2039 for more information on
the 07010 Calibration Unit and instructions to calibrate
the Combo Tester.
5. Repeat steps 2-4 for the second foot.
Maintenance
The Combo Tester requires little maintenance. There
are no user serviceable parts. If your meter requires
service beyond cleaning the test switch or foot plate,
please contact the factory.
Use a minimum of 80% isopropyl alcohol to clean the
test switch. Other cleaners are susceptible to leaving
residue.
BATTERY REPLACMENT
The low battery indicator flashes briefly every time
the unit is used. Replace the battery once the
indicator becomes constant during testing. Open
the compartment located on the back of the tester to
replace the battery. The tester uses one 9V alkaline
battery.
Figure 16. Desco 07010 Calibration Unit
Figure 15. Replacing the battery
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
TB-3069 Page 6 of 7
© 2016 DESCO INDUSTRIES, INC.
Employee Owned
Specifications
COMBO TESTER
Power Supply
9V Alkaline Battery or
optional AC power adapter
Operating Temperature
32°F to 104°F (0 to 40°C)
Wrist Strap Test Limit:
750 kilohms to 10 megohms
Footwear Test Limit:
750 kilohms to 100 megohms
Test Accuracy:
±20%
Test Voltage
4 VDC
Dimensions
3.3" x 5.6" x 1.5"
Weight
0.5 lbs
Limited Warranty, Warranty Exclusions, Limit of
Liability and RMA Request Instructions
See Desco Terms and Conditions
STAND AND FOOT PLATE
Stand Height
36"
Foot Plate Dimensions
18" x 12" x 1"
Weight
8.0 lbs
STAINLESS STEEL FOOT PLATE
Dimensions
20" x 20" x 0.5"
Weight
5.5 lbs
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
TB-3069 Page 7 of 7
© 2016 DESCO INDUSTRIES, INC.
Employee Owned